notes in SNG

I have my own ideas for notes on SNG.
I do take notes in SNG but only of the Multitablers and I look out their stats in OPR, it is easy to identify the players in 4 groups:
-very negative roi /(-20 to -5) maniacs that play lag early on and tight later
-slightly negative roi /(-5 to 0) players that are loose in the middle of the tournament and play weak tight in the bubble, itm
-slightly positive roi /(0 to 5) tight players that play well the whole sit but don't loosen up enough afterwards and do not adapt to the rising blinds, becoming vulnerable.
-winning players (5 to 30) guys that are paying attention, stealing blinds and play nicely push or fold.
- lucky bastards (40 +)
However this is only a generalization but it can be very helpful when making a choice in the middle stages of a tournament, for example it can be a hint for calling an all in on the flop. I agree with the fact that taking single notes on the ocasional players that are not multitablers is a waste of time.
What do you guys think of this method? Is it worth it?